Indicators of ancient woodland The use of vascular plants in evaluating ancient woods for nature conservation Francis Rose I t is a useful rule of thumb that the older the habitat, the more species it will support . And the more species it supports, the greater, in general terms, will be the site's importance for nature conservation. Hence, in theory, it should be possible to use the number of species present as an indication of habitat quality. In practice, however, there are drawbacks. It is exceedingly difficult to find out how many species of, say, insects or fungi are present, and even small sites would require many years to survey adequately. Mammals are too elusive, birds too mobile, and bryophytes or lichens often too difficult to identify to be useful indicators of habitat quality (with lichens the situ- ation is confused by air pollution and by coppice management, which eliminates many lichens of mature trees and causes large fluctuations in light levels and humidity). The only really useful group, which is both relatively easy to locate and identify, is the vascular plants, that is the flowering plants, April 1999 British Wildlife 241
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Indicators of ancient woodland The use of vascular plants in evaluating ancient woods for nature conservation
Francis Rose
It is a useful rule of thumb that the older the habitat, the more species it will support. And the more species it supports, the greater, in
general terms, will be the site's importance for nature conservation. Hence, in theory, it should be possible to use the number of species present as an indication of habitat quality. In practice, however, there are drawbacks. It is exceedingly difficult to find out how many species of, say, insects or fungi are present, and even small sites would require
many years to survey adequately. Mammals are too elusive, birds too mobile, and bryophytes or lichens often too difficult to identify to be useful indicators of habitat quality (with lichens the situation is confused by air pollution and by coppice management, which eliminates many lichens of mature trees and causes large fluctuations in light levels and humidity). The only really useful group, which is both relatively easy to locate and identify, is the vascular plants, that is the flowering plants,
April 1999 British Wildlife 241
Indicators of ancient woodland
Table 2 Ancient Woodland Vascular Plants in four regions of southern Britain . SW = south-west England (Cornwall, Devon , Somerset, Avon and Dorset); S = central-southern England (NCC 'South Region' - Hampshire, Wiltshire, Buckinghamshire, Berkshire and Oxfordshire); SE = south-east England (Kent, Surrey, Sussex, London and Hertfordshire); EA = East Anglia (Essex, Suffolk, Norfolk, Cambridgeshire).